cc: Remove use of PassAs() and constructor-casting with scoped_ptr.

Say you have class A and subclass B.

Previously it was required to PassAs() a scoped_ptr<B> into a
scoped_ptr<A>. This is no longer needed, so just use Pass(). For newly
created scoped_ptrs, you can just use make_scoped_ptr always now.

And when you want to return or assign an empty scoped_ptr(), you can
now use nullptr directly.

Also adds PRESUBMIT checks for:
- return scoped<T>(foo). This should be return make_scoped_ptr(foo).
- bar = scoped<T>(foo). This should be return bar = make_scoped_ptr(foo).
- return scoped<T>(). This should be return nullptr.
- bar = scoped<T>(). This should be return bar = nullptr.

This also replaces p.reset() with p = nullptr; But it does not add a
PRESUBMIT check for that because there are things other than scoped_ptr
with a reset() function.

R=enne@chromium.org

Review URL: https://codereview.chromium.org/609663003

Cr-Commit-Position: refs/heads/master@{#297096}

1 files changed, 1 insertions, 3 deletions

diff --git a/cc/input/top_controls_manager.cc b/cc/input/top_controls_manager.cc
index e972247..79353f2 100644
--- a/cc/input/top_controls_manager.cc
+++ b/cc/input/top_controls_manager.cc
@@ -180,9 +180,7 @@ gfx::Vector2dF TopControlsManager::Animate(base::TimeTicks monotonic_time) {
 }
 
 void TopControlsManager::ResetAnimations() {
-  if (top_controls_animation_)
-    top_controls_animation_.reset();
-
+  top_controls_animation_ = nullptr;
   animation_direction_ = NO_ANIMATION;
 }